Magnetostrictive transducer apparatus



Oct. 21, 1969 R. c. HEIM 3,474,271

' MAGNETOSTRICTIVE TRANSDUCER APPARATUS Filed June 8. 1967 i F IG.3.

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w I W WITNESSES INVENTOR Richard C. Heim x mm United States Patent O 3,474,271 MAGNETOSTRICTIVE TRANSDUCER APPARATUS Richard C. Heim, Ellicott City, Md., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., :1 corporation of Pennsylvania Filed June 8, 1967, Ser. No. 644,700 Int. Cl. H04r 9/02, 15/02 U.S. Cl. 310-26 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention Magnetostrictive transducer apparatus for ultrasonic agittaion of a liquid.

Description of the prior art Ultrasonic transducer apparatus in which thin U- shaped corrugation-containing laminations of magnetostrictive material are arranged with distributed spacing between laminations and are bonded at their one end to a radiating plate, as disclosed in U.S. Patents 3,161,792 and 3,173,037, are being employed with considerable success. The material and fabricating of such laminations and their mounting on the radiating plate tends to be somewhat costly.

SUMMARY According ot the present invention, the non-magnetic members couple the magnetostrictive material thereon to the plate at spacing intervals ddetermined by the thickness of such members, which may be varied to suit requirements. Fabrication of the novel vibratory elements and of the transducer assemblage is relatively simple.

BRIEF DESCRIPTION OF THE DRAWING FIGS. 1 and 2 are front and side elevation views of a magnetostrictive vibratory element constructed in accord with the present invention; and

FIGS. 3 and 4 are front and side elevation views of a novel transducer assemblage embodying vibratory elements constructed in accord with that shown in FIGS. 1 and 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the exemplified vibratory elements 5 of the present invention comprises a thin flat coupling member 6 of relatively inexpenssive non-magnetic material such as aluminum to opposite faces of which are bonded, as by epoxy cement, respective thin sheets 7 of magnetostrictive material, such as nickel, which extend the full width of such member and cover a portion one-half for example, of the length or height of such member ina mid-length region for maximum vibratory effectiveness. The member 6 is preferably one- 3,474,271 Patented Oct. 21, 1969 ice half wavelength long at the operating frequency, and the magnetostrictive sheets 7 are preferably one-quarter Wavelength long. The aluminum member 6 may be such as one-eighth inch thick which determines the spacing between abutting magnetostrictive sheets 7 on adjacent vibratory elements 5.

Referring to FIGS. 3 and 4, the novel vibratory elements 5 will be dimensioned to extend substantially the full width of the radiating plate 8 to which they are bonded at their one end, their output end, as by epoxy cement. The elements are arranged in groups 9, of Six or so, for example, with the elements 5 of each group abutting one another at their magnetostrictive sheets 7. To change the spacing of the abutting pairs of magnetostrictive sheets, the thickness of the aluminum member 6 would be made to suit.

For energizing the magnetostrictive sheets to vibrate the members 6 in a longitudinal mode, hence drive the coupling plate 8 uniformly across its face, each alternate group 9 of vibratory elements 5 is provided with a preformed coil 10 which encircles such group in the region of such magnetostrictive sheets. The adjacent groups not provided with their own coils are also driven by the nearby coils 10 via electromagnetic coupling therewith.

The radiating plate 8 may constitute the bottom of a cleaning tank 11 as shown for ultrasonic agitation of a liquid medium within such tank, or such plate may form the working wall of an immersible transducer (not shown) for disposition within a separate tank.

I claim as my invention:

1. A magnetostrictive vibratory element (5) comprismg:

a thin coupling member (6) of non-magnetic material for transmission of vibrational energy along its length to an output end; and

layers (7) of magnetostrictive material of less length than said coupling member secured to its opposite faces and disposed away from its output end.

2. The vibratory element of claim 1, wherein said coupling member (6) is of a thin, fiat, rectangular form and said layers (7) are of flat thin-sheet magnetostrictive material bonded to said member at a mid-length region thereof.

3. The vibratory element of claim 1, wherein said layers (7) of magnetostrictive material extend substantially the full'width of said coupling member (6) at a mid-length region thereof and are of a length substantially one-half that of said member.

4. The vibratory element of claim 2, wherein said coupling member (6) is of aluminum and said layers of thin-sheet magnetostrictive material are no greater than five mils thick.

5. A transducer assemblage comprising,

a thin flat radiating plate (8);

a plurality of flat parallel-arranged abutting vibratory elements (5) bonded at their one edge to a face of said radiating plate,

said vibratory elements each comprising a flat coupling member (6) of non-magnetic material having layers (7) of magnetostrictive material secured to opposite faces thereof at a mid-length region; and

preformed energizing coil means (10) electromagnetically coupled to said magnetostrictive layers (7 6. The transducer assemblage of claim 5, wherein the vibratory elements (5) are substantially the width of said radiating plate (8) and are arranged in groups (9) in their thickness direction, and said coil means (10) comprises a number of coils encircling every other one of such groups.

7. A transducer assemblage comprising,

a radiating plate,

a plurality of coupling members of non-magnetostrictive material bonded at their one edge to said radiating plate,

thin layers of magnetostrictive material bonded to surface regions of said coupling members and spaced away from their plate-bonded ends, and

energizing coil means electromagnetically coupled to said layers of magnetostrictive material.

References Cited UNITED STATES PATENTS 2,160,007 5/1939 Turner 3181l8 X 2,724,818 11/1955 Camp 3409 12/ 1964 Wright 31026 3/1965 Heim 31026 4/1968 Janssen 31026 FOREIGN PATENTS 8 1952 Italy.

MILTON O. HIRSHFIELD, Primary Examiner D. F. DUGGAN, Assistant Examiner US. Cl. X.R. 

